Technical data, for example the microscope's magnification, have heretofore been displayed mechanically or electrically on the microscope housing or on a display, in particular on a monitor. Video images have been presented via a monitor that was attached to the stand (see FIG. 1, existing art).
Such monitors are known, and so-called flat screens (e.g. TFT displays) are usually used today.
Surgical microscopes are indispensable in modern surgery. A magnification from 3× to 40× is selected as required. This allows surgeons to operate even on structures that are almost invisible to the naked eye, for example capillary blood vessels or nerves. Surgical microscopes also provide excellent illumination of the surgical field.
Surgical microscopes are used especially in neurosurgery, but also in other surgical specialties such as ear, nose and throat surgery, ophthalmology, and plastic and reconstructive surgery. Its light source is incorporated directly into the surgical microscope. The use of surgical microscopes makes it possible, for example in the case of microsurgical procedures on the brain or the spinal column, for incisions to be kept very small.
In the case of microsurgical procedures in particular, however, there are certain peculiarities as compared with procedures in which a surgical microscope is not used. For example, the surgeon and the surgical microscope must be located particularly close to the surgical field. The microscope body thus blocks the view of a surgical nurse, who can then observe the progress of the operation only on monitors in the operating room. Transfer devices on the surgical microscope serve this purpose. An anesthesiologist can also observe the progress of the operation via monitors in this fashion.
According to the presently existing art, however, a surgeon must also usually look at external monitors while working, in order to obtain additional information about the patient or about his equipment (e.g. phacoemulsifier, electrocautery, etc.). This requires turning one's head away from the microscope and toward the monitor, which is impractical and disadvantageous in terms of execution of the surgery.
Technical data of the surgical microscope and video images and external or internal data should therefore be shown to the surgeon at a point as close as possible to the surgical microscope, so that the surgeon does not need to look too far away from the surgical field. Data overlay systems that present their information directly in the microscope image have therefore been developed. This is achieved at present by means of a complex optical module in the interior of the microscope.